package zx.springcloud.lib;

import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;
import sun.security.jca.GetInstance;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author ZX
 * @date 2021/3/24
 */
@Component
public class MyLB implements  LoadBalancer
{

    private AtomicInteger atomicInteger= new AtomicInteger(0);

    public  final int getAndIncrement(){
        int current;
        int next;
        do{
            current = this.atomicInteger.get();
            //2147483647是整型最打的范围
            next = current>=2147483647?0:current+1;
         }while (!this.atomicInteger.compareAndSet(current,next));
         System.out.println("....第几次访问次数.next:"+next);
         return next;
    };

    @Override
    public ServiceInstance instances(List<ServiceInstance> serviceInstances)
    {

        int index =  getAndIncrement() % serviceInstances.size();

        return serviceInstances.get(index);
    }
}
